I'm 5'2", ktspktsp is 5'11"... but he is only about 8 lbs heavier than me, and I like the fact that we can toss each other around pretty much equally in that aspect. We wrestle all the time (not as foreplay! Just to wrestle and have fun, seriously) and it wouldn't be fun if he always won
I like having a more equal partner physically/strengthwise, though of course it's nice that I can fit under his chin and all that. I wouldn't like some huge muscle man, because then I'd always feel less strong... I don't care so much about protection, since I agree with Impetuous1 above that I'd rather fight alongside my man than stand back and scream for help and be a victim.
So I don't think height has much to do with it... just that the person would have to be about as strong and confident as I am, not too much stronger/more cocky. But that also has more to do with attitude... and a lot of short guys have bad/annoying attitudes, unfortunately! Napoleon complex, I guess. (Of course, if someone was shorter than ME, that would be rather odd... I'm a shrimp!)